The commander of U.S. and international forces in Afghanistan says it will likely be the end of the year before it is clear whether the effort to assert Afghan government control in the key southern city of Kandahar is succeeding.

U.S. Army General Stanley McChrystal says the Afghan and coalition effort in Kandahar has been going on for several months and will continue for several more, with a combination of military and civilian operations to expand the areas controlled by the Afghan government and to deliver security and services to the people.

And the general says just as the effort is gradual, without a formal starting date or a major military offensive, evidence of its effectiveness will also come slowly.

"I think it is going to be the end of this calendar year before you will know," he said. "I may know and feel before that. But I think that it will matter when the Afghan people know, and when the Afghan people have made that judgment. That will be the key point."

At a news conference near the end of the Washington visit by Afghan President Hamid Karzai, General McChrystal stressed the difficulties that lie ahead as the surge of U.S. and international forces continues and their operations, along with Afghan forces, intensify.

"This is a process that takes time," he said. "It will demand courage and resilience. We should expect increased violence as our combined security forces expand into Taliban-controlled areas."

The general repeated several times what he sees as the importance of sustaining the allied effort in order to convince the Afghan people that their future lies with the government rather than with the Taliban.

"In an area where there has been very little capacity before, to introduce that, is hard," he said. "And to convince the people is even harder because they watch the change in security, they watch the beginnings of governance, the beginnings of development, they have to see it to believe it. But they cannot just see it once. They have to see it until they believe it is durable, until they believe it is real."

The general said his priority is to deliver security and government services to Southern Afghanistan, particularly Kandahar. He said it is a "process" that involves attacking insurgent leaders, establishing and expanding security zones and other military operations, but also efforts by Afghan and international civilians to improve government services.

McChrystal said local tribal leaders will be continuously involved in planning, as President Karzai has promised, but he said they will not have veto power over specific military activities.

A senior U.S. officer who spoke on condition of anonymity says coalition and Afghan forces are creating a ring of security around Kandahar, and that American military police will be stationed at every Afghan police station in the city.

General McChrystal says he is applying lessons he learned earlier this year in the major operation to take the town of Marjah in neighboring Helmand Province .

"Tactically we learned pretty much what we expected," he said. "We knew they would use a huge number of IEDs [Improvised Explosive Devices]. Afghan forces performed well, but they are maturing as we go. We learned that partnering 'shana-by-shana,' shoulder-to-shoulder, with Afghan forces is the way to go. Coalition forces are better when we are shoulder-to-shoulder with Afghan forces, and they are better when they are shoulder-to-shoulder with us."

The general acknowledged that some Taliban fighters are trying to return to the town, and said that was expected, but will not change the outcome.

"They cannot come in and control Marjah like they did before. They cannot raise the flag. They cannot hold terrain. But they can try to convince the people that they are not secure - murders, night letters, taxation. And they can try to send a message that says 'this will not last, the coalition will leave, the government of Afghanistan will leave.' This gets to the heart of us making a credible performance over time to convince the people," he said.

General McChrystal said training Afghan security forces is his top strategic priority. He acknowledged there have been problems slowing the progress. News reports cite ethnic tensions, illiteracy, desertion and other difficulties. But recruiting has improved in recent months, and General McChrystal said he is pleased with the overall progress so far. Officials say developing a capable Afghan military and police force, and a government that can deliver services to the people, are the keys to the eventual withdrawal of foreign troops.

The general also discussed other aspects of the Afghan conflict. He said the reconciliation conference President Karzai is planning will be an opportunity to chart a way forward toward ending the conflict, in part through reconciliation with Taliban fighters and their reintegration into society.

He noted a good degree of cooperation with Pakistani forces involved in their own operations against insurgents on their side of the border. And he said the bombing attempt in Times Square last month, in which the Pakistani Taliban is believed to have had some involvement, is evidence of the importance of the Pakistani government's efforts.

And General McChrystal also said he will continue to stress to his troops the importance of protecting civilians even as the troops attack Taliban fighters who may be living and operating among the people. He said he will even consider giving medals to troopers who show extraordinary bravery in protecting Afghan civilians, the same medals they can earn for protecting their fellow troops.